I am making tiles coasters for Christmas presents. The first time I bought the tiles I bought the finished kind, stamped with stazon, colored them in and sealed them with Krylon sealer. I started using them for my coffee cup and they didn't hold up at all. They image is wearing off already and I haven't even been using them for a month. Then I went back to the drawing board. I bought the Tumbled Marble Tiles(sp?) from Home Depot. They were pretty pitted and not as smooth as I wanted. Back to the drawing board again! LOL I went to Lowe's and bought the Bottochino (sp?) Tumbled Marble Tiles. They come 9 to a box for around $6.00. I stamped them with Stazon and baked them in the oven. I don't think I had to bake them but it didn't hurt. I colored them with chalks and used Krylon Matte Sealer to seal them. If I didn't use chalk I don't think would have to seal them. These finally came out really nice. Here's a link to my tiles in the gallery.
Lovely As A Tree Coasters by shadowkat1283 at Splitcoaststampers
Kathy